docs: def get_current(self):
          """
          Parse the lease file and return a dict of active and valid Lease instances.
          The key for this dict is the ethernet address of the lease.
          """
          all_leases = self.get()
          leases = {}
          for lease in all_leases:
              if lease.valid and lease.active:
                  if type(lease) is Lease:
                      leases[lease.ethernet] = lease
                  elif type(lease) is Lease6:
                      leases['%s-%s' % (lease.type, lease.host_identifier_string)] = lease
          return leases